Effects of eruption guidance appliance in the early treatment of Class III malocclusion

OBJECTIVES

To evaluate the dentoskeletal effects and effectiveness of the eruption guidance appliance in Class III patients in the mixed dentition.

MATERIALS AND METHODS

The experimental group comprised 22 patients with Class III malocclusion and anterior cross-bite (12 males, 10 females, mean age 7.63 ± 0.96 years) treated with the eruption guidance appliance over a mean period of 1.72 ± 0.48 years. The control group comprised 22 untreated subjects (12 males, 10 females, mean age 7.21 ± 0.60 years) with Class III malocclusion. Lateral cephalometric radiographs were obtained at pretreatment (T1) and posttreatment (T2). Intergroup comparisons were performed with Mann-Whitney and t-tests (P < .05).

RESULTS

In the experimental and control groups, the anteroposterior relationship between the maxilla and mandible (ANB angle) remained stable during the treatment period (T1 to T2). The mandibular plane angle decreased in the experimental group and increased in the control group. In the experimental group, the lower anterior face height increase and maxillary molar vertical development were significantly smaller compared to controls. Positive overjet was achieved in 54% of the experimental group.

CONCLUSIONS

The eruption guidance appliance produced no change in the skeletal anteroposterior relationship. The anterior cross-bite/edge-to-edge relationship was corrected in only about half of the treated subjects.

Effect of four premolar extractions on the vertical dimension of the face : A retrospective cephalometric study

PURPOSE

Adequate control of the vertical dimension is of great importance in orthodontic treatment. Although existing evidence is very limited, extraction of four premolars is thought to contribute towards improved control of anterior facial height compared with non-extraction treatment protocols. Thus, the aim of this retrospective cohort study was to compare the effect of fixed-appliance treatment with extraction of four premolars to non-extraction treatment on the skeletal vertical dimension.

METHODS

A consecutive sample of 76 children with skeletal hyperdivergence (49% male; mean age 11.9 years) was divided into two groups for treatment with either non-extraction (n = 31) or extraction of four premolars (n = 45). Baseline characteristics were comparable: overjet 5.1 ± 2.5 mm, overbite 2.4 ± 1.9 mm, ANB angle 4.6 ± 2.3°, and SN-ML angle 40.2 ± 3.5°. Patients were treated with standard edgewise fixed appliances with closing loops/sliding mechanics. Vertical skeletal and dental outcomes were measured on lateral cephalograms before and after treatment. Data were analyzed with linear regression at 5%.

RESULTS

Compared to non-extraction treatment, treatment with premolar extractions had no significant effect on the SN-ML angle (difference (Δ) = 0.07°; 95% confidence interval -0.90 to 1.01°; P = 0.88). Statistically significant changes between the extraction and non-extraction groups were only found for the parameters SNA (Δ -1.47°; P = 0.003), ANB (Δ -1.17°; P = 0.004), SN-OP (Δ -1.48°; P = 0.04), and L1-ML (Δ -6.39°; P < 0.001).

CONCLUSION

Orthodontic treatment of children with skeletal hyperdivergence using systematic extraction of four premolars had minimal effects on the vertical facial dimension compared to non-extraction treatment.

Effect of micro-osteoperforations (MOPs) on the rate of en masse orthodontic tooth retraction : A randomized controlled trial

PURPOSE

To evaluate the effect of micro-osteoperforations (MOPs) on the rate of orthodontic tooth movement (OTM) during en masse anterior retraction.

MATERIALS AND METHODS

Twenty patients were randomly allocated into experimental and control group of 10 each. In the control group, en masse retraction was performed with sliding mechanics with a coil spring. In the experimental group after alignment and levelling, MOPs were performed mesially and distally to all six anterior teeth in the interdental cortical region on the labial aspect of both arches. MOPs were performed at the beginning of space closure (T0) and 1 month after beginning of space closure (T1). En masse retraction was performed with sliding mechanics with a coil spring. Measurements were recorded on digital models made from scanned plaster casts at the beginning of space closure (T0) and monthly at each follow-up visit for the next 4 months (T1, T2, T3, T4). The monthly rate of OTM, the overall rate of OTM, and the difference between OTM in the MOP period (T0-T2) and post-MOP (T2-T4) period in the experimental and control group were evaluated. A visual analogue scale (VAS) was used to evaluate patients' pain experience.

RESULTS

The overall rate of OTM was significantly greater in the experimental group for both arches in the MOP period (T0-T2) and also in the post-MOP period (T2-T4) as compared to the control group. Within the experimental group, the rate of OTM in the MOP period was significantly greater than in the post-MOP period, which in turn was greater than that of the control group. The patients reported only mild discomfort for 24 h after performing the MOPs, which then gradually decreased.

CONCLUSIONS

The use of MOPs is effective in increasing the rate of en masse tooth retraction in both the maxillary and the mandibular arch. The rate of tooth movement was greater even in the post-MOP period as compared to the control group.

A fully digital low-cost workflow of a multidisciplinary minimally invasive treatment: step-by-step from function to esthetics

This clinical case outlines a comprehensive digital workflow for a minimally invasive multidisciplinary treatment. The process utilizes one open-source software for digital wax-up and one low-cost software to address esthetic concerns related to teeth misalignment. The patient's function was stabilized with a digitally made occlusal splint. The application of the described digital workflow technique, incorporating open-source, low-cost, and closed software, played a pivotal role in attaining a straightforward and predictable outcome with minimally invasive treatment. Furthermore, the continual evolution of technology contributes to the growing precision of dental procedures. The presented digital workflow helped formulate a predictable treatment plan, replicate a diagnostic digital wax-up, and achieve precise teeth alignment. This approach satisfactorily addressed the patient's esthetic concerns, providing an outstanding approximation of the definitive result.

Study on decision-making for orthodontic treatment plans based on analytic hierarchy process

BACKGROUND

Orthodontics is a common treatment for malocclusion and is essential for improving the oral health and aesthetics of patients. Currently, patients often rely on the clinical expertise and professional knowledge of doctors to select orthodontic programs. However, they lack their own objective and systematic evaluation methods to quantitatively compare different programs. Therefore, there is a need for a more comprehensive and quantitative approach to selecting orthodontic treatment plans, aiming to enhance their scientific validity and effectiveness.

METHODS

In this study, a combination of the analytic hierarchy process (AHP) and semantic analysis was used to evaluate and compare different orthodontic treatment options. An AHP model and evaluation matrix were established through thorough research and semantic analysis of patient requirements. This model considered various treatment factors. Expert panels were invited to rate these factors using a 1-9 scale. The optimal solution was determined by ranking and comparing different orthodontic treatment plans using the geometric mean method to calculate the weights of each criterion.

RESULTS

The research indicates a higher preference for invisible correction compared to other orthodontic solutions, with a weight score that is 0.3923 higher. Factors such as comfort and difficulty of cleaning have been given significant attention.

CONCLUSION

The Analytic Hierarchy Process (AHP) method can be utilized to effectively develop orthodontic treatment plans, making the treatment process more objective, scientific, and personalized. The design of this study offers strong decision support for orthodontic treatment, potentially improving orthodontic treatment outcomes in clinical practice and ultimately enhancing oral health and patients' quality of life.

Digital setup accuracy for moderate crowding correction with fixed orthodontic appliances: a prospective study

OBJECTIVES

To evaluate the accuracy of a semi-automatic 3D digital setup process in predicting the orthodontic treatment outcome achieved by labial fixed appliances.

SUBJECTS AND METHODS

Twenty-five adult patients (18 to 24 years old) with class I malocclusion and moderate crowding were prospectively enrolled and received treatment on both jaws through the straight-wire technique. Prior to treatment commencement, a semi-automatic digital setup simulating the predicted treatment outcome was performed for each patient through Orthoanalyzer software (3Shape®, Copenhagen, Denmark) to obtain the prediction model. This was compared to the final outcome model through 3D superimposition methods. Metric variables and inspection of color-coded distance maps were used to detect how accurately the digital setup predicts the actual treatment outcome.

RESULTS

The mean absolute distances (MAD) between the superimposed dental arches of the predicted and the final models were: 0.77 ± 0.13 mm following superimposition on the palate, 0.52 ± 0.06 mm following superimposition on the maxillary dental arch, and 0.55 ± 0.15 mm following superimposition on the mandibular dental arch. The MAD at the palatal reference area was 0.09 ± 0.04 mm. Visualization of color-coded distance maps indicated that the digital setup accurately predicted the final teeth position in a few cases. Almost half of the cases had posteriorly wider upper and lower dental arches and palatally/lingually positioned or inclined anterior teeth, whereas the rest still showed errors within 2-3 mm, distributed over the entire dental arches with no distinct pattern.

CONCLUSIONS

The accuracy of semi-automatic prediction of the labial fixed appliance treatment outcome in Class I cases with moderate crowding is not yet sufficient. While average measures showed deviations less than 1 mm, examination of individual color-coded distance maps revealed significant disparities between the simulated and the actual results.

Aligner biomechanics: Where we are now and where we are heading for

Aligner orthodontics has gained significant popularity as an alternative to traditional braces because of its aesthetic appeal and comfort. The biomechanical principles that underlie aligner orthodontics play a crucial role in achieving successful outcomes. The biomechanics of aligner orthodontics revolve around controlled force application, tooth movement, and tissue response. Efficient biomechanics in aligner orthodontics involves consideration of attachment design and optimized force systems. Attachments are tooth-colored shapes bonded to teeth, aiding in torque, rotation, and extrusion movements. Optimized force systems ensure that forces are directed along the desired movement path, reducing unnecessary strain on surrounding tissues. Understanding and manipulating the biomechanics of aligner orthodontics is essential for orthodontists to achieve optimal treatment outcomes. This approach requires careful treatment planning, considering the mechanics required for each patient's specific malocclusion. As aligner orthodontics continues to evolve, advances in material science and treatment planning software contribute to refining biomechanical strategies, enhancing treatment efficiency, and expanding the scope of cases that can be successfully treated with aligners.

Does subsidized orthodontic treatment reduce inequalities in access? Evidence from Norway based on population register data

OBJECTIVE

An important part of Norwegian welfare policy is to provide subsidized orthodontic treatment for children and adolescents. The objective of this policy is that dental services should be allocated according to children's need for treatment, and not according to parents' ability to pay. The probability of receiving orthodontic treatment independent of parent's household income was examined.

METHODS

The study population encompassed children and adolescents aged 10-18 years in 2019 (n = 354 439). Information about whether they had started orthodontic treatment was obtained from the Norwegian Health Economics Administration. The key independent variable was net equalized household income. Inequalities were measured using concentration indices, which were estimated according to the severity of the malocclusion (very great need, great need, obvious need and no need). Two indices were used to measure relative inequality: the unstandardized concentration index and the partial concentration index. Absolute inequality was measured using the corrected concentration index. Relevant control variables were included in some of the analyses.

RESULTS

The unstandardized indices were in the range 0.04 (very great need) to 0.05 (obvious need). For all three groups of severity, the 95% confidence intervals overlapped. The values of the partial indices were significantly lower than the values of the unstandardized indices. The partial indices were in the range 0.008 (very great need) to 0.03 (obvious need). The 95% confidence intervals for the partial indices did not overlap with the 95% confidence intervals of the unstandardized indices. For all three groups of severity, the indices that measured absolute inequality were close to zero.

CONCLUSIONS

It is possible to achieve the egalitarian aim of equality in service provision by subsidizing orthodontic treatment. This is possible within a system where the cost of orthodontic treatment is reimbursed according to the criteria of need. These criteria function in such a way that patients with the greatest need for orthodontic treatment are given the highest priority.

Precautions and possibilities in orthodontic treatment of periodontally compromised patients: Current recommendations

OBJECTIVE

Orthodontic treatment plays a crucial role in achieving optimal dental esthetics and functional occlusion. However, when periodontally compromised patients are involved, additional precautions and considerations are critical. This article aims to provide up-to-date recommendations for the orthodontic treatment of periodontally compromised patients.

CLINICAL CONSIDERATIONS

Comprehensive diagnosis of the patient's periodontal status, inherent malocclusion, and secondary malocclusion resulting from periodontal disease are essential for achieving optimal esthetics and functional occlusion. This can be facilitated through the use of a simplified checklist. Prior to orthodontic treatment, pre-existing periodontal diseases should be managed. Light and controlled forces should be used to minimize the risk of adverse effects on the periodontium, and any potential traumatic occlusion during tooth movement should be minimized. Furthermore, careful anchorage management is required, and proper application of temporary anchorage devices can significantly expand the scope of orthodontic treatment. Finally, treatment results are maintained by ongoing supportive periodontal therapy even during the retention period.

CONCLUSIONS

This article presents clinical cases demonstrating the importance of accurate diagnosis in orthodontics and periodontics and the positive impact of orthodontic treatment on patients with pre-existing periodontal diseases.

CLINICAL SIGNIFICANCE

An up-to-date orthodontic treatment protocol for periodontally compromised patients is presented.

Innovations in Orthodontics: Skeletal Versus Dentoalveolar Expansion Utilizing Clear Aligners and TAD-Assisted Expanders

Hypoplastic maxilla is a common skeletal anomaly that compromises function and esthetics. Beyond just a narrow-appearing smile, this abnormality presents significant restorative challenges in adult patients as it is often associated with crowding, compromised axial inclination of the teeth, lack of alveolar bone support, root proximity, and occlusal trauma.1 Recent research also confirms association of maxillary deficiency with nasal stenosis and a predisposition to compromised nasal airflow and pharyngeal collapse during sleep.2,3 Maxillary transverse skeletal deficiency is often but not always associated with posterior dental cross-bite. In most cases, maxillary posterior teeth are flared buccally and mandibular posterior teeth are excessively lingually inclined masking the underlying skeletal problem.4 Advances in 3D imaging in dentistry, namely ultra-low radiation cone-beam imaging technology, have significantly enhanced clinicians' ability to diagnose and subsequently treat a maxillary transverse deficiency.5.

Multivariate analysis of alveolar bone dehiscence and fenestration in anterior teeth after orthodontic treatment: A retrospective study

OBJECTIVE

To compare the prevalence of fenestration and dehiscence between pre- and post-orthodontic treatment and to explore the factors related to fenestration and dehiscence in the anterior teeth after treatment.

METHODS

This study included 1000 cone-beam computed tomography (CBCT) scans of 500 patients before (T1) and after (T2) orthodontic treatment. These images were imported into Dolphin 11.9 software to detect alveolar fenestration and dehiscence in the anterior teeth area. The chi-square test and Fisher's exact test were performed to compare the prevalence of alveolar bone defects between time points T1 and T2. A total of 499 patients were selected for logistic regression analysis to examine the correlation among age, sex, crowding, sagittal facial type, extraction, miniscrew use and fenestration or dehiscence post-treatment.

RESULTS

Except for the maxillary lingual fenestration and labial fenestration of mandibular canines, a significant change in the prevalence of fenestration and dehiscence was noted between time points T1 and T2 (P < .025). Multinomial logistic regression showed that age, miniscrew use and extraction highly influenced the prevalence of anterior lingual dehiscence (P < .05). Dehiscence of the mandibular labial side (skeletal Class III vs. I, OR = 2.368, P = .000) and fenestration of the mandibular lingual side (skeletal Class II vs. I, OR = 2.344, P = .044) were strongly correlated with the sagittal facial type. Dehiscence of the maxillary labial side (moderate vs. mild, OR = 1.468, P = .017) was significantly associated with crowding.

CONCLUSIONS

Older age, maxillary moderate crowding, skeletal Class III, extraction and miniscrew potentially significantly affect the prevalence of anterior teeth dehiscence. Adult females, skeletal Class III patients on the mandibular labial side and skeletal Class II patients on the mandibular lingual side should be monitored for anterior teeth fenestration.

Malocclusion or laterorhinia: Which one impacts aesthetic facial perception the most?

INTRODUCTION

This study aimed to evaluate the perception of facial attractiveness when nose and teeth, together or isolated, present different degrees of disharmony. The secondary objective was to compare the perception of laypersons with that of dentists.

MATERIALS AND METHODS

This cross-sectional observational study included 112 individuals (58 laypersons and 54 dentists) that evaluated 6 manipulated images of the face of the same model, scoring their attractiveness using 10 cm Visual Analogue Scales (VAS), with least and most attractive at the left and right anchors, respectively. The images contained manipulations performed only on the nose (laterorhinia) and mouth (misaligned teeth), as follows: (1) standard photograph, with symmetrical nose + aligned teeth; (2) 2 mm nasal deviation + aligned teeth; (3) 4 mm nasal deviation + aligned teeth; (4) symmetrical nose + misaligned teeth; (5) 2 mm nasal deviation + misaligned teeth and (6) 4 mm nasal deviation + misaligned teeth. We used the repeated measures ANOVA test and Tukey's post-test for intra-group comparison of the images. The independent t-test was used for inter-group comparison of each image.

RESULTS

In the laypersons' group, the highest grades were given to images with aligned teeth and the lowest to misaligned teeth (smallest mean difference = 2.88 cm). For this group, there was no statistically significant difference (P-values ranged from .988 to 1.000) between scores of the three images in which teeth were aligned (range of 7.70-7.78 cm). In the group of dentists, highest grades were given to images with aligned teeth and the lowest to misaligned teeth. Difference between images 3 and 4 was not statistically significant (P = .204). All other differences between any image of straight teeth and any image with misaligned teeth were significant and the smallest mean difference between the two groups of images was 1.87 (P = .039). However, in the images with aligned teeth, there was also a statistically significant difference with higher scores to the images with symmetrical nose in contrast with those with significant laterorhinia (mean difference = 1.03 cm).

CONCLUSION

Teeth disharmonies had a more negative impact on the aesthetic perception of the face than did nose deviations, for both dentists and laypersons.

Orthodontic treatment demand for fixed treatment and aligners among young adults in middle Europe and South America - a questionnaire study

BACKGROUND

Patients experiencing any malocclusion, may desire for treatment. However, there is no scientific information orthodontic treatment demand and the knowledge of young adults about orthodontic treatment. The aim of the study was to assess orthodontic treatment demand in young adults from Poland and Chile, their previous orthodontic experience and their knowledge on fixed and aligner orthodontic treatment.

METHODS

The target group comprised people aged 18-30. The sample size was estimated as above 400 for each country. The survey was carried out in Polish and Spanish within 3 months and consisted of 25 questions delivered via social media. Comparisons were made between countries, age subgroups and gender.

RESULTS

The response rate was 1,99%, what stands for 1092 responses, 670 from Chile and 422 from Poland, respectively. The percentage of young adults who were already treated was 42,9% in Poland and 25,0% in Chile. The ones planning to have orthodontic treatment within a year counted for 11,8% in Poland and 5,3% in Chile. Most young adults who want to be treated (20,6%) rely on doctor's recommendation on type of appliance while 14,7% of all respondents are interested solely in aligners. Most respondents have heard about aligners (58%). Direct provider-to-customer service without a doctor is not acceptable, neither in Poland (85,1%) nor in Chile (64,8%). Most young adults provided incorrect answers referring various aspects of aligner treatment.

CONCLUSIONS

In both countries, patients demand to be treated and monitored by the orthodontist. A high percentage of patients want to be treated exclusively with aligners. Direct-to-consumer orthodontics does not seem attractive to patients. Young adults do not have adequate knowledge referring to aligner treatment. Many people want to be treated despite a previous orthodontic treatment.

Effect of maxillary anterior supernumerary tooth extraction on the underlying malocclusion

INTRODUCTION

Orthodontic discrepancies are a common finding in patients with supernumerary teeth (ST). The presence of a ST can cause a number of orthodontic discrepancies, including delayed eruption or retention of adjacent teeth, crowding, spacing, and abnormal root formation. The aim of the present study was to assess the effect of extraction of an anterior supernumerary tooth on the underlying orthodontic discrepancies without additional treatment for a 6-month period.

METHODS

This was a prospective, longitudinal, observational, study. It included 40 participants with orthodontic malocclusions due to maxillary anterior supernumeraries. We examined the changes in the crowding and excessive space in the anterior and posterior segments on cast models.

RESULTS

In the group that presented with crowding, a statistically significant decrease of 0.95 ± 0.17 mm (P < 0.001) was found between T0 and T1. Of the participants, three exhibited full self-correction. The excessive space at T0 (3.06 mm) decreased by 1.78 ± 0.19 mm to T1 (1.28 mm) in the anterior segment. Seven participants showed full self-correction of the diastemas after the 6-month observation period.

CONCLUSION

The results imply that orthodontic treatment can be postponed for at least 6 months after the extraction of the supernumerary tooth as potential self-correction can be expected. This natural alleviation of the malocclusions may make the orthodontic treatment simpler, shorten the treatment time and decrease overall appliance wear time.

Use of an intraoral scanner to evaluate orthodontic treatment for dental malocclusion in a dog

OBJECTIVE

In human dental practice, intraoral scanners (IOSs) are increasingly used to evaluate the oral cavity. However, there have been no reports concerning evaluation of the canine oral cavity using IOSs in veterinary dentistry. In this case, optical impressions obtained with an IOS were used for 3-D evaluation of the orthodontic treatment outcome. Additionally, few reports have addressed the optimal orthodontic force for canine teeth. Therefore, this case explored whether sufficient tooth movement into the extraction site could be achieved with a lighter orthodontic force than previously reported.

ANIMAL

An 8-month-old spayed female dog.

CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES

A retained right maxillary third deciduous incisor (503) caused distoversion of the right maxillary third permanent incisor (103), leading to dental malocclusion that involved contact between 103 and the right mandibular canine teeth.

TREATMENT AND OUTCOME

All retained deciduous teeth were extracted. Mesial tipping movement of 103 into the extraction site of 503 was achieved with light orthodontic force using an elastomeric chain. An IOS was used to construct 3-D optical impression data from oral stone models taken before and after treatment, and tooth movement was evaluated. The results showed that 103 had sufficient tipping movement and no anchorage loss; comfortable occlusion was achieved. In addition to crown length extension, labioversion and mesioversion of maxillary incisors (other than 103) were observed.

CLINICAL RELEVANCE

Detailed intraoral evaluation with optical impressions was beneficial in the orthodontic treatment of a dog. Light orthodontic force may be sufficient for movement into the extraction site.

Does short-term treatment with clear aligner therapy induce changes in muscular activity?

DESIGN

Prospective cohort study.

COHORT SELECTION

The inclusion criteria comprised patients older than 18 years who attended the orthodontic department at the University of L'Aquila (L'Aquila, Italy) and requested treatment with clear orthodontic appliance. Only patients with Class I malocclusion with mild (0-3 mm) or moderate (4-6 mm) crowding were included. The exclusion criteria comprised patients who had medical condition that preclude the use of surface EMG (sEMG), patients who had anterior or posterior open bite, patients who had cross bite that include more than one tooth, patients who had edentulous ridges and patients with temporomandibular disorder.

DATA ANALYSIS

Included patients were assessed at three points in time: at the start of treatment (T0), after 3 months (T1), and after 6 months (T2). The patients were instructed during the study to wear each set of aligners (Nuvola; Gruppo Europeo di Ortodonzia S.r.l., Rome, Italy) for 2 weeks and 22 h/d and to remove them while eating and drinking (except for still water). The following two assessments were done for each patient at T0, T1, and T2: surface electromyography (sEMG) evaluation and a T-Scan digital occlusal analysis evaluation. Both evaluations were performed in centric occlusion and with aligners worn. The assessments were done by the same operator. The sEMG evaluation aimed to assess the muscular symmetry and balance. The sEMG evaluation was performed using an instrument that recorded analogical sEMG signal (BTS TMJOINT, Teethan S.p.a., Garbagnate Milanese, Milano, Italy). The patients were instructed to clench as much as possible and to maintain the same level of contraction during the test. The software automatically selected the 3 s with the most stable sEMG signal. The following outcomes were assessed using the sEMG: 1. Masseter percentage overlapping coefficient (POC), temporalis POC, and mean POC: which is an index of the symmetrical distribution of sEMG potentials within homologous muscular couples. 2. Torque coefficient (TC): compares the activity of the temporalis muscle to that of the contralateral masseter muscle. 3. Activity index (Ac): compares the activity of the temporalis muscle to that of the homolateral masseter muscle 4. Asymmetry index (Asym): compares the activity of the temporalis and masseter muscles of the right side to those of the left side. The digital occlusal analysis was performed using a 100μ thin, flexible horseshoe-shaped Mylar sensor (Novus HD sensor, Tekscan, Inc. S. Boston, MA, USA) that is used to analyze the dynamic and real-time distribution and timing of occlusal contacts and can reproduce 256 levels of varying occlusal force. A first recording was made without aligners, then a second with the aligners worn on the dental arches. The following outcomes were assessed using the digital occlusal analysis: 1. Position of the center of occlusal force (COF). 2. The maximal intercuspation time (MIC) (i.e., the time interval expressed in seconds between the first dental contact and the maximal intercuspation). The null hypothesis was that no difference exists for the sEMG indexes between the 3-time points and the two occlusal conditions.

RESULTS

Twenty-six female adult patients (mean age, 33.67 ± 13.33 years) were enrolled in this study. Statistically significant differences were observed in terms of POC for the temporalis and masseter muscles, as well as the mean POC across the three time points and between occlusal conditions (with or without aligner). Hence, null hypothesis was rejected. On the other hand, TC, Ac, Asym, and MIC variables did not exhibit any statistically significant differences. This confirms that the stable positioning of COF on the transverse plane was accompanied by the absence of torquing muscular couples or imbalances in muscular activation. Symmetry in muscular couples' activation (indicated by POC value) remained consistent over the 6-month follow-up period for the occlusion with aligners, and in fact, demonstrated some improvements. In contrast, there was a decline in POC over time during centric occlusion. Statistically significant variation in COF position was observed in the sagittal plane, but not in the transverse plane. This shift in COF position coincided with changes in muscular balance as assessed by surface electromyography. Regarding the anteroposterior position of the COF, an overall slight posterior shift was observed when aligners were worn. After 3 months of full-time aligner usage, an anterior COF position was detectable in centric occlusion, which exhibited statistical significance when compared with the occlusion involving aligners at T0 and T1.

CONCLUSIONS

The use of clear aligners led to an anterior displacement of the COF during biting in centric occlusion, along with a posterior shift while the aligners were worn in healthy female subjects over a 6-month monitoring period. No significant asymmetries in the COF position on the transverse plane were observed. The alterations in occlusal contact were subsequently followed by a short-term improvement in muscular balance when aligners were used, but a worsening muscular balance over time in centric occlusion condition.

Soft tissue changes with skeletal anchorage in comparison to conventional anchorage protocols in the treatment of bimaxillary proclination patients treated with premolar extraction : A systematic review

PURPOSE

This review systematically evaluates the evidence related to comparisons between skeletal and conventional anchorage protocols in the treatment of bimaxillary proclination patients who underwent premolars extraction with respect to soft tissue profile changes, treatment duration and three-dimensional (3D) soft tissue changes.

METHODS

Electronic database search and hand search with no language limitations were conducted in the Cochrane Library, PubMed, Ovid, Web of Science, Scopus and ClinicalTrials.gov. The selection criteria were set to include studies with patients aged 13 years and above requiring extractions of upper and lower first premolars to treat bimaxillary proclination with high anchorage demand. Risk of bias assessment was undertaken with Cochrane's Risk Of Bias tool 2.0 (ROB 2.0) for randomised controlled trials (RCTs) and ROBINS‑I tool for nonrandomised prospective studies. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used for quality assessment. Results were summarised qualitatively; no meta-analysis was conducted.

RESULTS

Two RCTs and two nonrandomised prospective studies were included. According to the GRADE approach, there is low to very low quality of evidence that treatment using mini-implant anchorage may significantly change nasolabial angle, upper and lower lip procumbence, and facial convexity angle compared to treatment with conventional anchorage. Similarly, very low quality evidence exists showing no differences in treatment duration between treatments with skeletal or conventional anchorage.

CONCLUSIONS

The overall existing evidence regarding the effect of anchorage protocols on soft tissue changes in patients with bimaxillary protrusion and premolar extraction treatment plans is of low quality.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42020216684.

Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition

Since the introduction of Invisalign by Align Technology, Inc. in 1999, questions and debates have persisted regarding the precision of Invisalign (clear aligner) therapy, particularly when compared to the use of traditional fixed appliances. This becomes particularly significant in cases involving anteroposterior, vertical, and transverse corrections, where precise comparisons are of paramount importance. To address these inquiries, this study introduces a meticulously devised protocol, placing a primary emphasis on digitally superimposing the movement of maxillary posterior teeth to facilitate accurate analysis. The sample included 25 patients who had completed their first series of Invisalign (clear) aligners. Four maxillary digital models (pre-treatment, post-treatment, ClinCheck-initial, and final models) were digitally superimposed using the palate rugae and dentitions as stable references. A software combination was used for model superimposition and tooth segmentation. Transformation matrices then expressed the differences between the achieved and predicted tooth positions. Thresholds for clinically relevant differences were at ±0.25 mm for linear displacement and ±2° for rotation. Differences were assessed using Hotelling's T-squared tests with Bonferroni correction. The mean differences in rotation (2.036° ± 4.217°) and torque (-2.913° ± 3.263°) were significant statistically and clinically, with p-values of 0.023 and 0.0003 respectively. De-rotation of premolars and torque control for all posterior teeth were less predictable. All mean differences for the linear measurements were statistically and clinically insignificant, except that the first molars seemed slightly (0.256 mm) more intruded than their predicted position. The clear aligner system appears to meet its prediction for most translational tooth movements and mesial-distal tipping in maxillary posterior teeth for non-extraction cases with mild to moderate malocclusions.

An epidemiological study on early orthodontic treatment need among eastern Saudi Arabian children in the mixed dentition stage

Estimation of early orthodontic treatment need among children is essential for planning orthodontic interventions in the mixed dentition stages thereby reducing the burden in a publicly funded healthcare system. The present study aimed to assess the early orthodontic treatment need among children with mixed dentition in the Eastern Saudi Arabia. A descriptive cross-sectional study was conducted among Saudi children visiting the outpatient clinics in a University dental setting, and data were collected based on Index for preventive and interceptive orthodontic need (IPION). Descriptive statistics, chi-square test and Fisher's exact test were used for data analysis with statistical significance set at p < 0.05. The category of 'no treatment need' accounted for 11.3% while 'moderate treatment need' and 'definite treatment need' categories accounted for 29.3% and 59.4% respectively. There was no statistical difference between males and females in the distribution of the three categories of treatment need (p = 0.513). This study demonstrated a very high need for early orthodontic treatment among Saudi children in the mixed dentition stage. Emphasis should be placed on increased awareness and benefits of seeking early orthodontic treatment involving preventive and interceptive procedures in the mixed dentition.

Effects of clear aligners on the vertical position of the molar teeth and the vertical and sagittal relationships of the face: a preliminary retrospective before-after clinical trial

INTRODUCTION

Despite the popularity of clear aligners, their predictability has not been assessed adequately. Moreover, no study has investigated their effects on numerous dentomaxillary variables. Therefore, this study was conducted for the first time, assessing several new or controversial items. The aim of the study was to evaluate the effects of clear aligners on the vertical position of the molar teeth and the vertical and sagittal relationships of the face.

METHODS

This preliminary retrospective before-after non-randomized clinical trial was performed on 168 observations of 84 patients (33.60±9.28 years, 54 females) treated with 0.75mm Invisalign appliances. Pretreatment and posttreatment values were measured for: mandibular plane angle, occlusal plane angle, Y-Axis, ANB, facial angle, lower anterior facial height, overbite, and the distances of the molars from the palate and mandibular plane were measured. The alterations in parameters caused by treatment (delta values) were calculated for each measurement. Effects of treatment and some parameters on delta values were analyzed statistically (α=0.05).

RESULTS

Mean±SD of ΔMP-FH, ΔOP-FH, ΔY-Axis, ΔLAFH, ΔNPog-FH, ΔANB, ΔOverbite, ΔSNB, Δ6-PP, Δ7-PP, Δ6-MP, and Δ7-MP were respectively 0.11±1.61, 0.80±1.56, 0.15±1.18, 0.07±0.91, -0.22±1.25, 0.03±0.62, 0.04±1.15, -0.06±1.14, -0.36±0.94, -0.32±1.14, 0.19±0.96, 0.18±1.10. Only the alterations in OP-FH, 6-PP, and 7-PP were significant (P≤0.011). Age, sex, treatment duration, or pretreatment mandibular plane angle were not correlated with any delta values. However, the pretreatment occlusal plane angle was negatively correlated with ΔOP-FH and ΔY-Axis. Crowding was correlated negatively with ΔOP-FH and ΔY-Axis and positively with ΔNPog-FH. Overjet was negatively correlated with ΔANB and ΔOverbite (P≤0.035).

CONCLUSIONS

Invisalign intruded first/second maxillary molars and increased the occlusal plane angle. Age, sex, and treatment duration were not correlated with post-treatment anatomic alterations.

Orthodontic camouflage treatment for a patient with bilateral cleft lip and palate, bilateral crossbite, and microdontic maxillary lateral incisors

Cleft lip and palate is a congenital craniofacial anomaly that affects the lip and oral cavity. The management and orthodontic treatment of this anomaly is important but challenging. This article reports the successful treatment of a patient with bilateral cleft lip and palate, Class III malocclusion, bilateral crossbite, crowding and microdontic maxillary lateral incisors. One mandible incisor was extracted, and three miniscrew anchorages were utilized to distalize the maxillary left dental arch and retract the mandibular arch. After treatment, ideal occlusion and a better profile were established, and long-term stability was confirmed by a 4-year follow-up. This article represents a successful attempt of orthodontic camouflage treatment of severe dentofacial discrepancy, as an important part of the series treatment of cleft lip and palate, to provide some insight into the clinical field.

Effect of clear aligner type on maxillary full-arch intrusion: 3D analysis using finite element method

BACKGROUND

Vertical maxillary excess (VME) is one of the most common reasons for seeking orthodontic treatment. Total intrusion with aligners is a promising alternative to surgery in some cases. Considering the elastic deformation of aligners, this study aimed to evaluate the possible desirable and undesirable teeth displacements during full maxillary arch intrusion using clear aligners and temporary anchorage devices (TADs).

METHODS

The maxillary arch and clear aligners were modeled in SolidWorks. Four aligner brands including Leon, Duran, Duran Plus, and Essix Plus were selected based on their material properties. Anterior and posterior intrusion forces of 80 and 300 g were applied from attachments between the canines and first premolars and between the first and second molars, respectively. Vertical and anteroposterior tooth displacements were determined.

RESULTS

The greatest intrusion was recorded at the buccal of the second molar, followed by the first molar. The lowest value was measured at the palatal of the molars with all aligners except Duran, which indicated minimal intrusion in the central incisor. All teeth were mesially displaced at the incisal/occlusal except incisors that moved distally. All apices showed distal movement.

CONCLUSIONS

Total intrusion using clear aligners may be accompanied by other tooth movements, including buccal tipping and mesial-in rotation of the molars, retrusion of incisors, and mesial movement of other teeth.

Impact of orthodontic treatment on OHRQoL of adolescents: a longitudinal study

OBJECTIVE

The aim of this study was to evaluate the extent to which orthodontic treatment need is perceived by the patients and by the orthodontist, as well as the possible impacts on the OHRQoL (Oral Health-Related Quality of Life) over the course of conventional orthodontic treatment in adolescent patients.

METHODS

The sample consisted of 55 adolescents. The perception of patients and orthodontists relative to the malocclusion was evaluated by the IOTN (Index of Orthodontic Treatment Need). The OHRQoL was evaluated by the Child-OIDP (Child-Oral Impacts on Daily Performances) questionnaire before the conventional orthodontic appliance was bonded (T0); and at the following time intervals: after one week (T1), one month (T2), three months (T3), six months (T4), and after the end of orthodontic treatment (T5).

RESULTS

Adolescents who had large orthodontic treatment needs had a poor OHRQoL, according to their self-perception (p=0.003) and according to the orthodontist's perception (p<0.001), when compared with patients with small and moderate needs. There was statistically significant difference in the OHRQoL between the time intervals T0 and T1 (p=0.021), T2 and T3 (p<0.001), T3 and T4 (p=0.033), and T0 and T5 (p<0.002). At the end of treatment, all evaluated participants reported an improvement in OHRQoL.

CONCLUSIONS

It was concluded that adolescents and orthodontists agreed with regard to the perception of orthodontic treatment need. In the first week and in the first month of orthodontic treatment, there was a negative impact on the OHRQoL. After three months, an improvement of OHRQoL was detected, which has progressed over time.

Effectiveness of elastodontic appliances in the treatment of malocclusions: a review of the literature

AIM

This paper aims to verify the effectiveness of using elastodontic devices in the treatment of malocclusions in growing patients. An English-language literature search was conducted. The following electronic databases were selected for searching from 2020 to June 2023: PubMed, Web of Science, and Scopus. Eight articles were included based on the inclusion and exclusion criteria. The articles examined highlight the ability of elastodontic devices to act in cases of malocclusion in a safe, simple and more comfortable way for the young patient. However, there is a lack of knowledge about this technique, so this study aims to review the most recent literature to provide the scientific community with new knowledge.

Long-term stability of posterior crossbite correction, treated in the mixed or permanent dentition of growing children: A systematic review and meta-analysis

When treating posterior crossbite, the primary goal is to achieve long-term crossbite correction. The majority of studies however focus on relapse of the increase in the transverse dimension, but not relapse of the crossbite itself, which is an essential outcome. The aim of the present study was to determine long-term stability (2 years minimum post-treatment) of posterior crossbite correction, treated in mixed or early permanent dentitions of growing children. Following registration in PROSPERO (CRD42022348858), an electronic literature search including PubMed, Embase, Web of Science, the Cochrane Library, and a manual search were conducted up to January 2023, to identify longitudinal studies looking into the long-term stability of crossbite correction in growing children. Data extraction and risk of bias assessment were carried out, and subsequently, a random-effects meta-analyses models were used to calculate estimates for relapse of the crossbite and relapse at the transverse level. Twenty-two studies were included, of varying designs and quality, representing 1076 treated patients, with different expansion appliances and protocols. Meta-analysis results showed that 19.5% (95% CI: 15%; 25%) of patients present with relapse of posterior crossbite at long-term follow-up. At the transverse level, 19.3% of the total expansion (including overexpansion) relapsed (95% CI: 13%; 27%) regardless of whether there a was relapse of the crossbite itself. Data from existing studies, with a moderate level of evidence, indicate that the long-term stability of posterior crossbite correction in growing children is unfavourable in roughly 1 in 5 growing children, with crossbite relapse long-term. On average, 19% of the maxillary expansion performed (including overexpansion) relapses long-term, which may occur in cases with or without relapse of the crossbite.

Prevalence of KIG-grades 3-5 in an orthodontic practice in North Rhine Westphalia compared with results of the DMS•6 and with KZBV data

BACKGROUND AND AIM

The prevalence of tooth and jaw malocclusions in 8- to 9-year-olds was surveyed in a nationwide setting as part of the orthodontic module of the Sixth German Study on Oral Health (DMS•6), using the orthodontic indication groups (KIG) as index. Aim of this study was the detection of the prevalence of malocclusions requiring treatment according to the KIG index in statutorily insured patients of an orthodontic practice in North Rhine Westphalia, Germany, and to compare results with corresponding DMS•6 and KZBV data.

PATIENTS AND METHODS

Between 2017-2021, n = 953 statutorily insured patients called for an initial consultation and subsequent determination of the KIG-classification and -grades. The malocclusions were classified and graded in the highest possible KIG-grade according to valid SHI guidelines. Multiple classifications were not recorded. KIG-grade > 3 according to the valid guidelines was detected in n = 815 patients. Since the DMS•6 does not contain information on KIG classifications "U" and "S", their inclusion was waived despite evaluation, leaving data from n = 683 patients for analysis and comparison.

RESULTS

During the study period, n = 235 patients (34.4%) had KIG-classification "D". More than 10% were classified as "K" (120 patients, 17.6%), "P" (98 patients, 14.2%), "M" (89 patients, 13.0%), and "E" (81 patients, 11.9%). Of 16 possible classifications with KIG-grade > 3, "D4" was the most common with 26.6% (182 patients). The results confirm the findings from the multicentric DMS•6 from2021 and corresponding KZBV data from 2020.

CONCLUSIONS

Sagittal deviations described by classifications "D" and "M" represent with 47.4% almost half of the malocclusions with treatment need. KIG-grade D4 is the most frequent classification. There were no regional deviations of the prevalence of KIG-grades 3-5 in the district of Viersen / North Rhine compared with the national average, not even when scrutinizing a five-year-period.

Evaluation of the impact of orthodontists' smile with malocclusions on social media and professional credibility

OBJECTIVES

This study assessed laypeople's perceptions of orthodontist credibility based on malocclusions and whether these views affect their choice to seek treatment. Eye-tracking technology and questionnaires were utilized.

MATERIALS AND METHODS

Ninety-five lay raters, through eye tracking and a questionnaire, assessed 12 images of orthodontists with malocclusions. Malocclusions were categorized by the Index Of Treatment Need (IOTN) as grade 1 (near ideal), 3 (anterior crowding), and 5 (with diastemas). Fixation points were recorded, and credibility was gauged via questionnaires. A Mentimeter word cloud was generated.

RESULTS

IOTN 1 orthodontists were viewed as more credible than IOTN 3 (p < 0.001) and 5 (p < 0.001). Raters were more willing to receive treatment from IOTN 1 orthodontists. The focus for IOTN 1 was between eyes and mouth, while IOTN 3 and 5 were on the mouth. "Crooked teeth" and "spacing" were predominant in word clouds for IOTN 3 and 5.

CONCLUSION

Orthodontists with an IOTN grade 1 rating were perceived as more competent, reliable, and professional, thus making it more likely for laypeople to choose them as their preferred providers.

CLINICAL RELEVANCE

The smiles of professionals play a significant role in laypeople's decision to choose them as their orthodontist, and strategic utilization of social media can effectively deliver health information to a larger audience in a faster and more direct manner.

Effects of nasoalveolar molding on maxillary arch dimensions and malocclusion characteristics in primary dentition patients with cleft lip and palate

BACKGROUND

Nasoalveolar molding (NAM) is a presurgical orthopedic technique used in the management of cleft lip and palate deformities. Despite the widespread use of NAM therapy, there is a need for further investigation to assess its specific effects on arch dimensions and malocclusion characteristics.

AIM

To evaluate the effects of NAM therapy on maxillary arch dimensions and malocclusion characteristics in patients with unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP).

DESIGN

Patients in primary dentition were referred to the Institutional Department of Orthodontics. The NAM group consisted of 21 patients with UCLP (mean age 4.7 ± 0.7 years) and 12 patients with BCLP (mean age 4.8 ± 0.7 years). Sixteen patients with UCLP (mean age 4.9 ± 0.9 years) and five patients with BCLP (mean age 5.4 ± 1.1 years) were included in the non-NAM group. The plaster models of all patients were digitized. Dental arch dimensions and malocclusion characteristics were analyzed via digital software. One-way ANOVA with Bonferroni correction was used for statistical analysis.

RESULTS

Intercanine and intermolar widths showed statistically significant differences according to the cleft type (p < .01). There was no statistically significant effect of NAM therapy on maxillary arch parameters and malocclusion characteristics (p > .05). The prevalence of anterior crossbite was 12.1% in the NAM group and 23.8% in the non-NAM group.

CONCLUSION

NAM therapy did not affect the maxillary arch dimensions and malocclusion characteristics in patients with UCLP and BCLP. The cleft type was the main factor, leading to a significant difference in maxillary widths.

Initial development of an 'Orthodontic Care Index' involving treatment need,-complexity and-priority

BACKGROUND/OBJECTIVES

The aim of this study was to develop an evidence-based scoring system for prioritizing limited orthodontic resources based on orthodontic treatment need (OTN), orthodontic treatment complexity (OTC), and orthodontic treatment priority (OTP), which is not merely a scoring system for malocclusion but also a comprehensive classification of orthodontic issues incorporating patient- and treatment-related factors, called Orthodontic Care Index (OCI).

MATERIALS AND METHODS

The development of the OCI involved eight phases, starting with a systematic literature review to identify all possible parameters involved in determining OTN, OTC, and OTP. An eight-member orthodontic specialist panel then evaluated and scored the significance of each parameter, resulting in a parameter-score list. Subsequently, a retrospective convenience sample of 61 patients was scored with the parameter-score list, and using the same convenience sample a gold standard was established through the expert opinion of a third orthodontic panel. Linear regression analysis was used to estimate weights of importance and construct a formula to calculate index scores. Lastly, the expert opinion was compared to the index scores, to determine the index performance.

RESULTS

The preliminary index separately calculates OTN, OTC, and OTP for a patient as the weighted sum of his/her domain scores. The sensitivity of the index for predicting OTN, OTC, and OTP was high (98.1%, 82.9%, and 92.7% respectively), while the variability of each was relatively low (52.1%, 31.2%, and 52.6% respectively).

CONCLUSIONS/IMPLICATIONS

The OCI shows promise as a guideline for prioritizing orthodontic care. It will be further refined and validated to enhance its performance and usefulness.

Biomechanical model registration for monitoring and simulating large orthodontic tooth movements in the maxilla and mandible

PURPOSE

Superimposition of digital dental-arch models allows quantification of orthodontic tooth movements (OTM). Currently, this procedure requires stable reference surfaces usually only present in the maxilla. This study aimed to investigate the accuracy of a novel superimposition approach based on biomechanical principles of OTM and the equilibrium of forces and moments (EFM)-applicable in both jaws-for monitoring and simulating large OTM.

METHODS

The study included 7 patients who had undergone extraction of the first (PM1-Ex) or second (PM2-Ex) premolar in each quadrant. Digital models taken at start and end of the T‑Loop treatment phase were superimposed by applying 3 EFM variants differing in the number of teeth used for registration. Maxillary OTM results for EFM were validated against those for a conventional surface registration method (SRM). In an additional case study, OTM were simulated for PM1-Ex, PM2-Ex and non-extraction treatment strategies.

RESULTS

The EFM variant that included all teeth of the dental arch achieved the highest accuracy, with median translational and rotational OTM deviations from SRM of only 0.37 mm and 0.56°, respectively. On average, retracted canines and first premolars were distalized by 3.0 mm, accompanied by 6.2° distal crown tipping and 12.2° distorotation. The share of space closure by molar mesialization was 19.4% for PM1-Ex quadrants and 34.5% for PM2-Ex quadrants.

CONCLUSION

EFM allows accurate OTM quantification relative to the maxillary and mandibular bases even in challenging situations involving large OTM. Superimposition of malocclusion and setup models enables realistic simulation of final tooth positions. This may greatly enhance the value of digital setups for decision-making in orthodontic treatment planning.

Changes in the swallowing pattern and tongue posture during the transition from deciduous to mixed dentition-a longitudinal ultrasonography study

BACKGROUND

Given the importance that swallowing pattern and tongue posture might have in the aetiology of malocclusion, it appears important to be aware of the physiological changes of tongue function and its posture.

OBJECTIVES

The study aimed to assess changes of the swallowing pattern and tongue posture during the transition from the deciduous to mixed dentition and the association between them.

MATERIALS AND METHODS

The study included 57 subjects aged 5.87 ± 0.5 with normal occlusion, orofacial functions, no history of trauma, or orthodontic treatment. Ultrasonography was used for the assessment of tongue posture and swallowing pattern, where the spontaneous act of swallowing was recorded. To evaluate the possible effect of incisors' eruption, the swallowing pattern and tongue posture ultrasonograms were compared at the deciduous (DD), early mixed (EMD), and intermediate mixed (IMD) timepoints.

RESULTS

A significant association between the swallowing pattern and tongue posture at the DD and IMD timepoint was found. Moreover, the visceral swallowing pattern decreases with age (odds ratio [OR] = 0.777), as well as with a prolonged phase IIa (OR = 0.071), while it increases when the tongue is postured on the mouth floor (OR = 5.020).

LIMITATIONS

The young age of the investigated subjects, direct contact of the probe, and the determination of the rest phase of the tongue were considered limitations.

CONCLUSIONS

No statistically significant changes in swallowing pattern and tongue posture occurred during the transition period; however, a significant association between the swallowing pattern and tongue posture among subjects with normal occlusion, regardless of the dentition phase was detected.

Effect of mandibular third molars on crowding of mandibular teeth in patients with or without previous orthodontic treatment: a systematic review and meta-analysis

OBJECTIVES

To assess the scientific evidence related to the role of the mandibular third molars on the late crowding of the lower anterior teeth in patients with or without previous orthodontic treatment. The secondary outcomes included changes in mandibular arch width and arch length.

MATERIALS AND METHODS

The databases PubMed, Scopus, ProQuest, and Google Scholar were searched from inception until April 2022. The included papers were studies evaluating the role of mandibular third molars on crowding of mandibular anterior teeth in patients of any age and gender, with mandibular third molars impacted or semi-impacted or erupted. Predetermined and prepiloted data collection forms were used to record the necessary information.

RESULTS

Thirteen observational studies were included in the present systematic review. Most of them were assigned an overall risk of bias of moderate risk while the rest of them were at high risk. Four studies found an association between the presence of mandibular third molar and mandibular incisor crowding. Finally, seven studies were included in the quantitative analysis. Three different meta-analyses were conducted: for patients (a) with or (b) without previous orthodontic treatment and (c) in combination for patients with and without previous orthodontic treatment. According to the pooled results of all three meta-analyses, random effects model yielded a significant benefit for those without third molars compared to those with third molars regarding crowding, mean Little's irregularity index and mean arch length.

CONCLUSIONS

Lower third molars may contribute to mandibular crowding and lower arch constriction. Further prospective research of high quality is needed to clarify the impact of third molars on anterior mandibular crowding.

Association between crowding estimation and extraction recommendations in orthodontics

INTRODUCTION

Little is known about how precisely orthodontists in the United States (US) assess crowding or at what range of crowding they recommend extraction. This study aimed to assess the relationship between estimated crowding in patients with a Class I relationship and extraction recommendation by orthodontists in the US. The secondary aims were to evaluate the accuracy and precision of clinician estimations and determine if clinician background traits play a role in extraction decision-making.

METHODS

An electronic survey was prepared using 4 patients with a Class I relationship with anterior crowding selected from a University Orthodontics Clinic and was sent to approximately 10,400 subjects through Facebook and the American Association of Orthodontists Partners in Research program.

RESULTS

From the 297 responses received, most clinicians recommended extraction once crowding reached 9-10 mm in either the maxilla or the mandible. The data from 2 patients suggest this decision was more strongly correlated with mandibular crowding. Clinician estimations varied widely but, on average, were precise within approximately 2 mm of objective measurements. There was a tendency to overestimate crowding, especially by Northeastern practitioners. Clinicians who reported routinely measuring crowding or who reported that they recommended extractions to >10% of their patients were 1.2-2.0 and 1.4-1.6 times more likely, respectively, to recommend extraction in the patients.

CONCLUSIONS

Crowding estimation was highly subjective and varied widely among clinicians. Most clinicians recommended extraction once maxillary or mandibular crowding approximated 9-10 mm. Some clinician demographics were correlated with the precision and accuracy of estimations and the likelihood of extraction in the patients.

The predictability of arch expansion with the Invisalign First system in children with mixed dentition: a retrospective study

This study aimed to quantify the predictability of arch expansion in children with early mixed dentition treated with the Invisalign First® system and evaluate the clinical factors for the predictability of arch expansion. Pretreatment, predicted and posttreatment digital models from Invisalign's ClinCheck® software were obtained for 90 children with mean (standard deviation) age of 8.42 (0.93) who planned arch expansion. Arch width measurements were collected using Invisalign's arch width table. The predictability of expansion was calculated by comparing the amount of expansion achieved with the predicted expansion. Linear regression analysis was used to evaluate clinical factors associated with predictability of expansion. The predictability of the expansion of the maxillary teeth was as follows: 71.1% primary canines (n = 55), 67.5% first primary molars (n = 46), 65.2% second primary molars (n = 79), and 53.4% first permanent molars (n = 90); the predictability of the expansion of the mandibular teeth was 81.1% primary canines (n = 31), 81.2% first primary molars (n = 51), 77.8% second primary molars (n = 80), and 69.4% first permanent molars (n = 90). The predictability of arch expansion was significantly higher in the mandibular arch compared to the maxillary arch and significantly lower in the permanent first molar than in the other primary teeth. Predictability decreased significantly as the amount of predicted expansion per aligner increased in the upper and lower permanent first molars, primary second molars, and upper primary canines. Predictability significantly increased when buccal or palatal attachments were placed on the bilateral side compared to cases without attachment at the upper permanent first and primary second molars. The predictability of arch expansion using the Invisalign First® system varies according to arch and tooth type. The amount of predicted expansion per aligner and the number of attachments to the maxillary teeth are potential clinical factors that can affect the predictability of expansion.

Three-dimensional evaluation of dentopalatal changes after rapid maxillary expansion in growing children

INTRODUCTION

In growing children with transverse malocclusion problems, various types of rapid maxillary expanders (RMEs) have been effectively used in skeletal and dental expansions. We evaluated 3-dimensional dentopalatal changes in growing children who underwent maxillary expansion using RMEs and bonded RMEs.

METHODS

We investigated dentopalatal changes in 20 patients treated with bonded RMEs, 19 with RMEs, and 38 control patients. Dental plaster models before and after expansion were scanned 3-dimensionally and superimposed to evaluate transverse expansion, expansion ratio, angular expansion, and palatal expansion height ratio.

RESULTS

Using bonded RMEs, similar anterior and posterior dental expansions were achieved with an efficiency of 69%-76% (expansion ratio), and palatal soft-tissue expansion occurred more apically in the posterior area (palatal expansion height ratio, 1.00) than in the anterior area (palatal expansion height ratio, 0.64). Using RMEs, a larger posterior dental expansion was achieved, with an efficiency of 106%-117% (expansion ratio), than anterior dental expansion (55%-60%), and palatal soft-tissue expansion occurred more apically in the posterior area (palatal expansion height ratio, 0.99) than anterior area (palatal expansion height ratio, 0.23).

CONCLUSIONS

Dental expansions in the anterior and posterior areas were similar using bonded RMEs, whereas the posterior dental expansions were larger than those of the anterior area using RMEs. The entire palatal soft-tissue slope expanded in the posterior area, whereas the occlusal part expanded in the anterior area using RMEs and bonded RMEs.

Orthodontic treatment and biological limits: a retrospective clinical trial

BACKGROUND

The fundamental part of every successful orthodontic treatment is the detailed treatment planning including a precise determination of the virtual treatment objective (VTO) while considering the biological and anatomical limits. The aim of this study is to investigate and to compare the feasibility of the established reference values before and after orthodontic treatment and to determine the usefulness of this parameters as guidance for the sagittal anterior, sagittal posterior and transverse biological boundaries.

MATERIALS AND METHODS

Thirty-two patients aged 9 to 18 years (12 male and 20 female) with all permanent teeth present were randomly selected for orthodontic treatment with fixed multibracket appliance regardless of the potential malocclusion. The parameters 6-PTV, 1-NB [mm] and the WALA ridge were set for the identification of the transverse, sagittal anterior and sagittal posterior tooth position. The measurements were carried out at the beginning (T0) and at the end (T1) of the orthodontic treatment. They were set in relation with their individual threshold values (G). After the results of the measurements were conducted using the software OnyxCeph3TM (version 3.2.185 (505), Image Instruments GmbH, Chemnitz, DE), they were statistically calculated in the software RStudio (2022.12.0 Build 353 © 2009-2022 Posit Software PBC).

RESULTS

Among the 32 patients, the mean pre- and post-treatment changes measured through the three parameters in relation to the individual reference values were statistically significant (p < 0.01). The mean values for 6-PTV, 1-NB and the WALA ridge amounted 15.37 mm, 2.56 mm and 4.23 mm at the beginning of the treatment, while after the treatment the measured values amounted 20.31 mm, 2.4 mm and 5.55 mm. These measurements combined with the statistical analysis of the changes of WALA ridge (T0, T1) confirmed that the teeth have been successfully uprighted and aligned. Furthermore, the maxillary first molars have been moved slightly mesially, as proven by the changes in 6-PTV, without certainty as to whether bodily movement or mesial tipping took place. Additionally, the lower incisors have been protruded, slightly exceeding the individual threshold values.

CONCLUSION

The parameters investigated provide a suitable assessment tool for recording the limits of the sagittal posterior, the sagittal anterior and the transverse dimension.

Factors influencing treatment outcomes assessed by the American Board of Orthodontics Objective Grading System (ABO-OGS)

BACKGROUND

Treatment outcomes can be influenced by various factors. This study aimed to determine the association between predisposing patient- and treatment-related factors (demographic, cephalometric parameters, skeletal relationships, Discrepancy Index (DI), extractions, treatment type and duration) and treatment outcomes measures according to the American Board of Orthodontics Objective Grading System index (ABO-OGS).

METHODS

Completed cases (N = 100) were included in this cross-sectional study. One calibrated examiner assessed DI, pretreatment lateral cephalometric parameters and ABO-OGS. Patient data, including sex, age, types of malocclusion, extractions, treatment type, and duration, were also collected. Intraexaminer reliability for each measurement was evaluated using the intraclass correlation coefficients. Multiple linear regression analysis, using the backward elimination method with a significance level (α) of 0.05, was used to determine which factors significantly influenced the ABO-OGS score.

RESULTS

From the study, the overall mean ABO-OGS score was 11.36 points. Factors influencing the ABO-OGS score were pretreatment Wits values (p value = .000), L1-NB (°) (p value = .023) and treatment duration (p value = .019). Subjects with lower negative values of Wits and L1-NB (°) tended to have higher ABO-OGS scores. Additionally, the ABO-OGS score tended to be higher for subjects with longer treatment times.

CONCLUSIONS

The majority of treated subjects had satisfactory orthodontic treatment outcomes assessed by the ABO-OGS. The pretreatment severity of skeletal discrepancies determined by the Wits parameter, the degree of retroclined lower incisors and longer treatment duration negatively impacted the treatment outcomes.

Analysis of maxillary asymmetry before and after treatment of functional posterior cross-bite: a retrospective study using 3D imaging system and deviation analysis

BACKGROUND

Previous evidence would suggest that subjects affected by functional posterior cross-bite (FPXB) present an asymmetric morphology of the maxilla. However, no evidence is available concerning the morphology (symmetry/asymmetry) of the maxilla after treatment of FPXB. This study aimed to investigate the volumetric and morphological changes of the palate in FPXB subjects treated with maxillary expansion and to compare these data with an untreated control group. The study sample included 20 FPXB subjects (mean age 8.1 ± 0.9 years) who underwent maxillary expansion (MEG group) and 21 FPXB subjects (mean age 7.7 ± 1.2 years) as controls (CG group). Digital models were recorded at T0 (first observation) and T1 (12-18 months after first observation) and analyzed to assess palatal volume and symmetry. Deviation analysis and percentage matching calculation were also performed between original and mirrored palatal models for each patient. All data were statistically analyzed for intra-timing, inter-timing and inter-groups assessments.

RESULTS

At T0, the cross-bite side (CBS) was significantly smaller than non-cross-bite side (non-CBS) in both groups (p < 0.05). At T1, the CBS/non-CBS difference reduced significantly in the MEG group (p < 0.05) while slightly worsened in the CG, however without statistical significance (p > 0.05). The matching percentage of the palatal models improved significantly at T1 in the MEG group (T0 = 74.02% ± 9.8; T1 = 89.95% ± 7.12) (p < 0.05) while no significant differences were recorded in the CG (T0 = 76.36 ± 8.64; 72.18% ± 9.65) (p > 0.05).

LIMITATIONS

The small sample size and the retrospective design of the study represent two limitations that should be overcome with further clinical trials.

CONCLUSIONS

Subjects with FPXB present an asymmetric development of the maxillary vault that improves after reestablishment of normal occlusion following maxillary expansion.

[Technical specification for orthodontic transmission straight wire technique]

Malocclusion is an oral disease with a high prevalence. The goal of orthodontic treatment is health, aesthetics, function and stability. The transmission straight wire appliance and technique is an innovative orthodontic system with independent intellectual property rights invented by Professor Jiuxiang Lin's team based on decades of clinical experience, which provides a new solution for the non-surgical correction of skeletal malocclusions, especially class Ⅲ malocclusion, and it is also a good carrier for the implementation of the concept of healthy orthodontics. Due to the lack of guidelines, how to implement standardized application of transmission straight wire technique remains a problem to be solved. This technical specification was formed by combining the guidance from Professor Jiuxiang Lin and joint revision by a number of authoritative experts from the Orthodontic Special Committee, Chinese Stomatological Association, with reference to relevant literatures, and combined with abundant clinical experience of many experts. This specification aims to provide reference to standardize the clinical application of transmission straight wire technique, so as to reduce the risk and complications, and finally to improve the clinical application level of this technique.

Assessment of clear aligner accuracy of 2 clear aligners systems

INTRODUCTION

This study compared treatment efficacy for specific tooth movements between 2 clear aligner systems (Clarity [3M Oral Care Solutions, St Paul, Minn] and Invisalign [Align Technology, San Jose, Calif]).

METHODS

The study sample included 47 patients (7 males, 40 females; mean age, 36.57 ± 15.97 years) treated with Invisalign and 37 (4 males, 33 females; mean age, 34.30 ± 16.35 years) treated with Clarity aligners who completed their first set of aligners and had an initial refinement scan. Initial and predicted models were obtained from the initial simulated treatment plan. The first model of the refinement scan was labeled as achieved. SlicerCMF software (version 3.1; http://www.slicer.org) was used to superimpose the achieved and predicted digital models over the initial ones with regional superimposition on the relatively stable first molars. Nine hundred forty teeth in the Invisalign system were measured for horizontal, vertical, and angular movements and transverse width and compared with similar measurements of 740 teeth for the Clarity aligners. The deviation from the predicted was calculated and compared between both systems.

RESULTS

The deviation achieved from the predicted was significant between the groups for the mandibular interpremolar and intercanine widths (P <0.05). Clarity aligners significantly undercorrected rotations compared with Invisalign for the mandibular first premolars, mandibular canines, maxillary canines, and maxillary central incisors. There was no statistically significant difference between the groups for the achieved vs predicted movements in the horizontal and vertical planes (P >0.05).

CONCLUSIONS

The efficacy of clear aligner therapy systems (Clarity and Invisalign) in treating mild and moderate malocclusions was comparable. Deviation of the achieved movements from the predicted was greatest for rotational and vertical movements.

An adult case of unilateral posterior crossbite caused by maxillary transverse deficiency treated with miniscrew-assisted rapid palatal expansion

This report describes the successful treatment of an adult case of unilateral posterior crossbite caused by maxillary transverse deficiency with miniscrew-assisted rapid palatal expansion (MARPE). A female patient aged 35.5 years presented with masticatory disturbance, facial asymmetry, and unilateral posterior crossbite. She was diagnosed with unilateral posterior crossbite with a skeletal Class III jaw-base relationship and high mandibular plane angle. Her maxillary right and mandibular bilateral second premolars were congenitally absent, and the maxillary left second premolar was impacted. After the improvement of the posterior crossbite with MARPE, 0.018″ slot lingual brackets were placed on the maxillary and mandibular dentition. The total active treatment period was 22 months, and acceptable occlusion with a functional Class I relationship was achieved. Pretreatment and posttreatment cone-beam computed tomography images showed the disarticulation of the midpalatal suture after MARPE, and changes in the dental and nasomaxillary structures, nasal cavity, and pharyngeal airway. The case results demonstrate that MARPE produces greater skeletal expansion with minimal buccal tipping of the molars. MARPE may be effective for the treatment of maxillary transverse deficiency in adult patients.

Treatment effectiveness of young adults using clear aligners versus buccal fixed appliances in class I malocclusion with first premolar extraction using the ABO-Objective Grading System: A randomized controlled clinical trial

OBJECTIVE

To compare the effectiveness of the clear aligners with the traditional fixed appliances in the treatment of premolars extraction complex cases using the American Board of Orthodontics Objective Grading System (ABO-OGS).

MATERIAL AND METHODS

A single-centre, 2-parallel groups RCT with two arms. Forty severe crowding patients (14 males, 26 females; mean age: 21.40±2.42) who required four first premolars extraction were included and randomly allocated into two treatment groups: clear aligners therapy group (CAT), and fixed appliances therapy group (FAT). Cases complexities were measured on pre-treatment records using the Discrepancy index (DI). Post-treatment records were evaluated using the American Board of Orthodontics Objective Grading System (ABO-OGS). Two sample t-tests and Fisher's Exact tests were used to test for significant differences between the two groups. The statistical significance was set at P < 0.006 using Bonferroni's correction.

RESULTS

For the DI, the mean scores were 32.25 (± 4.33) in the CAT group and 33 (± 7.92) in the FAT group. In the CAT group, the total OGS score ranged between 6-33 points with an average of 17.50(± 7.41), whereas the total score in the FAT group went between 4-30 points with an average of 12.89 (± 6.31) with no significant differences between the two groups (P=0.05). When comparison of the successful cases between the two groups was made, 11 cases received passing scores, and 9 cases received failing scores in the CAT group. Whereas in the FAT group, 17 cases received passing scores, and 3 received a failing score. No statistically significant differences were found in the passing rates between of the CAT and FAT groups (P = 0.421).

CONCLUSIONS

According to the ABO-OGS total scores, there was no significant difference between the clear aligners and fixed appliances in the treatment of class I severe crowding cases with first premolars extraction in young adults. There were no differences between the two techniques in the OGS components scores except for the occlusal contacts, which were significantly better with the fixed appliances. When comparing the number of successful and failed cases between the two groups, no significant differences were noted, with the fixed appliances having a 30% higher success rate than the clear aligners, which must be considered clinically when choosing between these two techniques in the complex orthodontic cases treatment.

Digital treatment planning and clear aligner therapy: A retrospective cohort study

OBJECTIVE

To investigate the total number of digital treatment plan (DTPs) and aligners manufactured for clear aligner therapy (CAT) by Invisalign® from initial treatment planning to the completion of CAT.

DESIGN

A retrospective cohort study.

MATERIAL AND METHODS

A total of 30 patients, from each of 11 experienced orthodontists, who commenced treatment over a 12-month period, were assessed regarding the number of DTPs and aligners prescribed from initial planning to completion of CAT. Patients were categorised according to the number of aligners prescribed by the initial DTP into mild (<15), moderate (15-29) or severe (>29).

RESULTS

After the application of inclusion/exclusion criteria, 324 patients (71.9% women; median age = 28.5 years) undergoing non-extraction treatment with the Invisalign® appliance were assessed. The median number of initial DTPs was 3 (interquartile range [IQR] = 2, 1-9) per patient before acceptance by the orthodontist. Most (99.4%) patients required a refinement phase with a median of 2 (IQR = 2, 2-7) refinement plans recorded. A total of 9135 aligners per dental arch, was prescribed in the initial DTP of the 324 patients assessed and 8452 in the refinement phase. The median number of aligners per dental arch prescribed from the initial DTP was 26 (IQR = 12, 6-78) and from the refinement plans was 20.5 (IQR = 17, 0-132).

CONCLUSION

A median of three initial DTPs and two refinement plans were required for patients undergoing non-extraction treatment with the Invisalign® appliance. Patients were prescribed almost double the number of aligners initially predicted to manage their malocclusion.

Frequency and severity of malocclusions in patients with statutory health insurance in a German orthodontic practice in North Rhine Westphalia - a multi-part cross-sectional study over a 20-year period

OBJECTIVE

Since 2002, patients with statutory health insurance in Germany must undergo an assessment of orthodontic treatment need using the "Kieferorthopädische Indikationsguppen" (KIG; orthodontic indication groups) classification system. According to this system, tooth and jaw misalignment are divided into 11 subgroups and five grades. The objectives of this study were to determine the distribution of KIG classifications in patients with statutory insurance of a German orthodontic practice (North Rhine, Germany) and to analyze changes over a 20-year period.

MATERIALS AND METHODS

Since the introduction of the KIG index in 2002, 4940 statutorily insured patients over a 20-year period (2330 m, 2610 f, min 3.2, max 49.5 years, peak between 10 and 12 years) were classified at their first appointment. According to the valid guidelines of the statutory health insurance (GKV), the division was made into the highest possible KIG classification. Multiple entries were thus not made. In accordance with the operating cycles of the practice, the progression was divided into four 5-year periods.

RESULTS

Over a 20-year period, 24.98% of the patients were assigned to the classification "D". 86.52% of the patients were among the 6 most frequently ("D", "E", "K", "S", "P" and "M", > 10% each) and only 13.49% among the 5 least frequently recorded classifications ("U", "B", "T", "O" and "A", < 5% each).

CONCLUSION

The distribution of the 6 most frequent and the 5 least frequent KIG classifications was constant over a 20-year-period. Among all possible tooth and jaw misalignment variants, the sagittal classifications "D" and "M" represent the most frequent malocclusions.

CLINICAL RELEVANCE

The results and their comparison with historical data show that both frequency and severity of tooth and jaw misalignment with orthodontic treatment need appear identical for patients with statutory health insurance over a 20-year period.

The impact of orthodontic treatment on a young person's quality of life, esthetics, and self-esteem in hypodontia: A longitudinal study

INTRODUCTION

This research aimed to evaluate the impact of orthodontic treatment on a young person's oral health-related quality of life, self-esteem, and esthetics concerning hypodontia.

METHODS

A prospective longitudinal hospital-based study recruited 97 participants with hypodontia, aged 11-18 years. Forty-one participants (42%) originally planned to have space closure and the remainder space opening, with subsequent prosthetic replacement. The following questionnaires were completed before and after orthodontic treatment: the child perception questionnaire, Bristol condition-specific questionnaire for hypodontia (BCSQ), the child health questionnaire, and the Oral Aesthetic Subjective Impact Scale (OASIS). The Wilcoxon and matched pairs t tests approach was applied to compare before and after orthodontic treatment for significant testing (P <0.05).

RESULTS

Fifteen participants were lost to follow-up, resulting in 82 participants completing orthodontic treatment, with an average age of 13.8 ± 1.71 years. A total of 282 teeth were missing in the sample. Treatment resulted in significantly lower indexes (P <0.001) to overall BCSQ, OASIS, appearance, and how others would treat them. In comparing the 2 subgroups, those treated with space closure had significantly reduced functional limitations (child perception questionnaire), appearance concerns, self-esteem (child health questionnaire), OASIS, and overall BCSQ scores.

CONCLUSIONS

Orthodontic treatment in participants with hypodontia appears to significantly impact a range of psychological and esthetic scales. In particular, space closure appears to significantly improve the quality of life of participants compared with those undergoing space opening.

Profile changes in extraction treatments of upper premolars: A case series

This case series describes the soft tissue changes following extraction treatment in two patients with diverse lip thickness, but with similar baseline parameters including: labial competence, soft tissue profile, patient's age, extraction protocol, methods of anchorage, malocclusion, crowding, treatment appliance and mechanics. The same treatment plan involved upper first premolar extractions and lingual appliance combined with skeletal anchorage. The lip thickness played a crucial role in these cases, since a similar change of the incisor position leads to a different profile variation. This difference could be explained by the differing initial lip thicknesses as the patient with thin lips showed a more pronounced profilometric change. The choice of the ideal treatment plan must be tailored to the individual patient, taking into account not only initial skeletal and dental factors but also soft tissue factors, as well as the treatment goals.